#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>

#include "config.h"
#include "mp_msg.h"

#include "img_format.h"
#include "mp_image.h"
#include "vf.h"

struct vf_priv_s {
	int w, h;
	int method; // aspect method, 0 -> downscale, 1-> upscale. +2 -> original aspect.
	int round;
	float aspect;
};

static int config(struct vf_instance* vf,
	int width, int height, int d_width, int d_height,
	unsigned int flags, unsigned int outfmt)
{
	if (vf->priv->aspect < 0.001) { // did the user input aspect or w,h params
		if (vf->priv->w == 0) vf->priv->w = d_width;
		if (vf->priv->h == 0) vf->priv->h = d_height;
		if (vf->priv->w == -1) vf->priv->w = width;
		if (vf->priv->h == -1) vf->priv->h = height;
		if (vf->priv->w == -2) vf->priv->w = vf->priv->h * (double)d_width / d_height;
		if (vf->priv->w == -3) vf->priv->w = vf->priv->h * (double)width / height;
		if (vf->priv->h == -2) vf->priv->h = vf->priv->w * (double)d_height / d_width;
		if (vf->priv->h == -3) vf->priv->h = vf->priv->w * (double)height / width;
		if (vf->priv->method > -1) {
			double aspect = (vf->priv->method & 2) ? ((double)height / width) : ((double)d_height / d_width);
			if ((vf->priv->h > vf->priv->w * aspect) ^ (vf->priv->method & 1)) {
				vf->priv->h = vf->priv->w * aspect;
			} else {
				vf->priv->w = vf->priv->h / aspect;
			}
		}
		if (vf->priv->round > 1) { // round up
			vf->priv->w += (vf->priv->round - 1 - (vf->priv->w - 1) % vf->priv->round);
			vf->priv->h += (vf->priv->round - 1 - (vf->priv->h - 1) % vf->priv->round);
		}
		d_width = vf->priv->w;
		d_height = vf->priv->h;
	} else {
		if (vf->priv->aspect * height > width) {
			d_width = height * vf->priv->aspect + .5;
			d_height = height;
		} else {
			d_height = width / vf->priv->aspect + .5;
			d_width = width;
		}
	}
	return vf_next_config(vf, width, height, d_width, d_height, flags, outfmt);
}

static void uninit(vf_instance_t *vf) {
	free(vf->priv);
	vf->priv = NULL;
}

static int open(vf_instance_t *vf, char* args)
{
	vf->config = config;
	vf->draw_slice = vf_next_draw_slice;
	vf->uninit = uninit;
	//vf->default_caps = 0;
	vf->priv = calloc(sizeof(struct vf_priv_s), 1);
	vf->priv->aspect = 0.;
	vf->priv->w = -1;
	vf->priv->h = -1;
	vf->priv->method = -1;
	vf->priv->round = 1;
	if (args) {
		if (strchr(args, '/')) {
			int w, h;
			sscanf(args, "%d/%d", &w, &h);
			vf->priv->aspect = (float)w/h;
		} else if (strchr(args, '.')) {
			sscanf(args, "%f", &vf->priv->aspect);
		} else {
			sscanf(args, "%d:%d:%d:%d", &vf->priv->w, &vf->priv->h, &vf->priv->method, &vf->priv->round);
		}
	}
	if ((vf->priv->aspect < 0.) || (vf->priv->w < -3) || (vf->priv->h < -3) ||
			((vf->priv->w < -1) && (vf->priv->h < -1)) ||
			(vf->priv->method < -1) || (vf->priv->method > 3) ||
			(vf->priv->round < 0)) {
		mp_msg(MSGT_VFILTER, MSGL_ERR, "[dsize] Illegal value(s): aspect: %f w: %d h: %d aspect_method: %d round: %d\n", vf->priv->aspect, vf->priv->w, vf->priv->h, vf->priv->method, vf->priv->round);
		free(vf->priv); vf->priv = NULL;
		return -1;
	}
	return 1;
}

const vf_info_t vf_info_dsize = {
    "reset displaysize/aspect",
    "dsize",
    "Rich Felker",
    "",
    open,
    NULL
};